sayre



Feb. 14, 1956 R. H. SAYRE 2,734,246

PRODUCTION OF PERFORATE CERAMIC WARE Filed Nov. 26, 1952 ll-ll l INVENTOR.

", RAY H.SAYRE.

' ATTORNEYS.

United States Patent PRODUCTION OF PERFORATE CERAMIC WARE Ray H. Sayre, Pittsburgh, Pa.

Application November 26, 1952, Serial No. 322,689 3 Claims. CI. 25-44 My invention relates to the production of ceramic ware on a potters wheel, and more particularly to the production of perforated dishes or plates.

Heretofore perforated dishes or plates of the sort in mind have been produced by the slip casting method, which is well known to those skilled in the art. The production of ceramic ware by such method is substantially more costly than production upon a potters wheel.

The invention will be described as it has been practiced in the production of perforated plates.

Referring to the drawings,

Fig. l is a view in plan of a dinner plate that is perforated around its rim portion;

Fig. 2 is a view of the plate in diametrical cross section;

Fig. 3 is a view of a potters wheel, showing the plate mold on the wheel partly in side elevation and partly in vertical section;

Fig. 4 is a view similar to Fig. 3, showing additionally, however, a pancake of plastic ceramic material in place upon the mold, ready to be fashioned into the form of a plate; and

Fig. 5 is another view similar to Fig. 3, but showing a profile in position of cooperation with the mold for shaping the pancake into the form of the plate. I

Referring to the drawings, the reference numeral is applied to a plate, forming a product of the invention herein illustrated in exemplary way. The rim 3 of the plate includes a plurality of perforations 4. The perforated plate is formed on the mold 7 of a potters wheel 5 in cooperation with a profile 9 (Fig. 5) that may be operated in conventional manner. The top of the mold 7, which mold may be formed of plaster of Paris or bisque, includes a matrix within a peripheral rim (to which the reference numeral 7 is immediately applied on Fig. 3), and such matrix is in the precise shape of the top of the plate 2, and in the production of such plate a plastic pancake 8, formed of a mixture of ceramic material and water, is slapped upon the mold, in the position illustrated in Fig. 4.

The potters wheel is borne upon the upper end of a shaft 6, which is driven to rotate the wheel and mold rapidly on the vertical axis of the shaft. The profile 9, comprising a thin blade whose lower edge 10 conforms to the section of the bottom surface of the plate (cf. Fig. 5), is carried at the lower end of a spindle 90. In service the potters wheel and its mold, with the pancake of plastic ceramic material thereon, are rotated relatively to the profile 9, while the profile is moved downward relatively to the rotating mold, to place the contoured edge Iii of the profile at work. The profile distributes the ceramic material and shapes it to the matrix of the mold, and simultaneously the working edge 10 of the profile fashions the top of the pancake to the form of the bottom of the plate. Between the mold and the profile the pancake is fashioned into the precise form of the plate. Any excess ceramic material gathers against the body of the profile, whence it is readily removed and returned to the batch.

2,734,246 Patented Feb. 14, 1956 When the moist ceramic material has been completely jiggered or formed, the profile is raised and the mold 7 with the formed plate is removed from the wheel and placed in a drying room. The moisture content is evaporated from the shaped ceramic material on the mold, and in the drying process the ceramic material shrinks slightly and becomes sufficiently rigid for handling. In due course the shaped article is lifted from the mold, and such decorating and glazing substances as desired are applied. Then the article is placed in a sagger and fired in usual manner, vitrifying the body and applied glazing material of the article and producing the finished plate.

In accordance with my present invention, I provide integrally with the mold body 7 and within the rim of the mold matrix a boss or protuberance 12 for each of the perforations 4 desired in the plate 2. The bodies of the bosses 7 are in plan of the same outline as the perforations desired in the plate; each boss rises or projects from the surface of the matrix of the mold a distance exactly equal to the thickness of the rim of the plate in which the corresponding perforation is to be formed; the peripheral side surface 20 of each boss tapers or is drafted convergently outward from the surface of the mold matrix; and the outer or upper end or face of each boss is dished, as at 13, whereby a peripheral edge M is formed.

The working edge 10 of the profile includes an edge portion 11 which cooperates with the peripheral edges 14 of the several bosses 12; when the potters wheel and mold are in rotation and the profile is moved into plateforming position (Fig. 5). The working edge of the profile uniformly distributes and shapes the plastic ceramic material in the mold matrix and around the bodies of the bosses 12, while the profile edge portion 11 cleanly severs the ceramic material fiush with peripheral edges 14 of the bosses and sweeps any surplus material before it for removal in usual manner. Such small quantities of ceramic material as remain in the dished portions of the bosses are severed at the boss edges 14 from the body of the material that has been jiggered into the form of the plate.

When a pancake of ceramic material has thus been fashioned into an article in the form of the perforated plate 2, the mold 7 and the shaped article are removed to the drying room for subsequent treatment in conventional way. It is important to note that during the drying and shrinking of the formed article the tapered or drafted sides of the bosses 12, under the contraction of the drying and shrinking ceramic material, cause the body of the article to rise slightly from the surface of the matrix and thus prevent the body of the plate from crack ing under the incidental compressive stresses, which it would otherwise tend to do. After the ceramic article has been dried and becomes rigid, it is decorated, glazed and fired in usual way, to form the finished product of Figs. 1 and 2.

The small quantities of ceramic material remaining in the dished ends 13 of the bosses 12 after the jiggering and drying operations are readily removed, and the mold is ready for use again on the potters wheel.

It is to be noted that l have illustrated and described the production of a dish or plate having a relatively simple set of perforations, but it will be understood that a more complex system of perforations may be formed in the product in accordance with the teaching of my invention. For example, lace platesplates whose rims include complicated filigree designs that have the appearance of lace-may be produced on a potters Wheel in accordance with the teachings hereof, rather than by the slip casting method, which has hitherto been employed. It is merely necessary to provide in the matrix of the potters wheel mold a system of tapered bosses and protuberances in counterpart of the system of perforations desired in the finished product.

Within the terms of the appended claims many variations and modifications of structure and process described may be made without'departing from the spirit of the invention.

I claim:

1. Apparatus for the manufacture of perforated ceramic articles, said apparatus comprising a rotary potters wheel having a mold thereon to receive a pancake of plastic ceramic material, a boss outstanding on the face of the matrix of said mold, the sides of said boss tapering con vergently outwardly from the face of said matrix, and a profile movable relatively to the rotary potters wheel for cooperation with said mold in causing said boss to penetrate the body of said pancake and in shaping said plastic ceramic material thereof, said profile including a shearing edge portion for cooperation with the outer end of said boss, and said outer end of the boss being dished and including a peripheral edge for cooperation with said shearing edge-portion of the profile.

2. In apparatus for the manufacture of perforated ceramic articles comprising a rotary potters wheel having a mold thereon to receive a pancake of plastic ceramic material, and a profile for cooperation with the matrix of said mold in the formation of said article, said matrix including a rim portion for cooperation with the profile in forming the outer periphery of the finished article; the improvements herein described comprising a plurality of protuberances rising in the mold matrix to a height equal to the body thickness of said article and being spaced from each other and spaced inwardly from the rim portion of the matrix that cooperates with said profile in the formation of the periphery of the finished article, said profile being movable relatively to the potters wheel for distributing and shaping the plastic ceramic material of the pancake applied to the mold over and between said protuberances and to the form of said matrix and effecting a penetration of the protuberances through the ceramic material in the matrix, said profile including a shearing edge-portion for cooperation with the outer ends of said protuberances.

3. Apparatus for the manufacture of a perforate plate comprising a profile, a potters wheel having a mold with a matrix to receive a charge of plastic ceramic material, said matrix having a rim portion for cooperation with said profile in the formation of the periphery of the finished plate and a plurality of outwardly drafted protuberances rising in said mold matrix to a height equal to the thickness of the plate and being spaced inwardly from said rim portion and from each other, said profile being movable relatively to the potters wheel in rotation for distributing and shaping the ceramic material over and between said protuberances and to the form of said matrix, and effecting the penetration of the protuberances through said ceramic material, said profile including a shearing edge-portion for cooperation with the outer ends of said protuberances.

References Cited in the file of this patent UNITED STATES PATENTS 533,212 Crossley Jan. 29, 1895 1,441,704 Neuenschwander Jan. 9, 1923 2,183,944 Salisbury Dec. 19, 1939 2,506,378 Miller May 2, 1950 FOREIGN PATENTS 27,836 Great Britain Dec. 16, 1896 

